This application relates to thermostat devices, and more particularly to thermostat devices with bimetallic and magnetic elements.
One type prior art thermostat is known from U.S. Pat. No. 3,656,082, wherein the thermostatic switch has a ferromagnetic armature which is normally attracted by a fixed magnet and is selectively attracted by a movable magnet fixed to a bimetal. Another type thermostat with a magnetic switch is shown in U.S. Pat. No. 3,593,236, wherein the switch points are enclosed in a glass structure and include an armature that is magnetically movable to effect different connection arrangements of the switch points.
In U.S. Pat. No. 4,748,432, a switch lever rotates a bimetal to set a desired temperature, and a stopper is employed to hold the contacts together so that regardless of the ambient temperature, the blower motor remains on. Room thermostats for controlling heating and cooling systems are also shown in U.S. Pat. No. 3,190,988, which illustrates an embodiment wherein a bimetal element carries on its free end a permanent magnet to activate a glass enclosed magnetically responsive switch. U.S. Pat. No. 3,171,003 describes a thermostat with a bimetal operated switching device in which a switch operator has a permanent magnetic with a variable reluctance shunt for changing the operation differential of the device.
Earlier prior art arrangements are also shown in U.S. Pat. Nos. 1,867,756 and 1,881,950. The '950 patent is of the type where the bimetallic member controls a mercury switch member, and the '756 patent is of the type where the bimetallic member controls movement of the armature arm of a magnetic.
In order to improve, simplify, and overcome limitations found in the foregoing and other prior art, it is an object of the invention to provide an improved thermostat device with a bimetallic element and a magnet positioned and movable to activate a reed switch.